Merge "Add support for Generic Telephone Bearer service (GTBS)" am: b8e22b665b am: 62e998f7ad am: 6ee60434a0 am: cf724aa60f

Original change: https://android-review.googlesource.com/c/platform/packages/services/Telecomm/+/1942896

Change-Id: I3353a52ddfafca3a7a9bc10c3bd521fd8e1867ae